Results 31 to 40 of about 217,791 (313)

Full one-loop amplitudes from tree amplitudes [PDF]

open access: yes, 2008
We establish an efficient polynomial-complexity algorithm for one-loop calculations, based on generalized $D$-dimensional unitarity. It allows automated computations of both cut-constructible {\it and} rational parts of one-loop scattering amplitudes ...
  +21 more
core   +2 more sources

On the Cuts of Scattering Amplitudes [PDF]

open access: yesNuclear Physics B - Proceedings Supplements, 2008
The use of complex analysis for computing one-loop scattering amplitudes is naturally induced by generalised unitarity-cut conditions, fulfilled by complex values of the loop variable. We report on two techniques: the cut-integration with spinor-variables as contour integrals of rational functions; and the use of the Discrete Fourier Transform to ...
openaire   +4 more sources

Tropical fans, scattering equations and amplitudes

open access: yesJournal of High Energy Physics, 2021
We describe a family of tropical fans related to Grassmannian cluster algebras. These fans are related to the kinematic space of massless scattering processes in a number of ways.
James Drummond   +3 more
doaj   +1 more source

ANALYTIC SCATTERING AMPLITUDES FOR QCD [PDF]

open access: yesProceedings of the Conference in Honor of C N Yang's 85th Birthday, 2008
By analytically continuing QCD scattering amplitudes through specific complexified momenta, one can study and learn about the nature and the consequences of factorization and unitarity. In some cases, when coupled with the largest time equation and gauge invariance requirement, this approach leads to recursion relations, which greatly simplify the ...
Diana Vaman, York-Peng Yao
openaire   +4 more sources

Massive on-shell supersymmetric scattering amplitudes

open access: yesJournal of High Energy Physics, 2019
We introduce a manifestly little group covariant on-shell superspace for massive particles in four dimensions using the massive spinor helicity formalism.
Aidan Herderschee   +2 more
doaj   +1 more source

Soft radiation from scattering amplitudes revisited

open access: yesJournal of High Energy Physics, 2021
We apply the recently developed formalism by Kosower, Maybee and O’Connell (KMOC) [12] to analyse the soft electromagnetic and soft gravitational radiation emitted by particles without spin in D ≥ 4 dimensions.
A. Manu   +3 more
doaj   +1 more source

Scatterings of Massive String States from D-brane and Their Linear Relations at High Energies [PDF]

open access: yes, 2006
We study scatterings of bosonic massive closed string states at arbitrary mass levels from D-brane. We discover that all the scattering amplitudes can be expressed in terms of the generalized hypergeometric function with special arguments, which ...
Bachas   +38 more
core   +2 more sources

Pion-pion scattering amplitude [PDF]

open access: yesPhysical Review D, 2005
We obtain reliable ππ scattering amplitudes consistent with experimental data, both at low and high energies, and fulfilling appropriate analyticity properties. We do this by first fitting experimental low energy [s^(1/2) ≤ (1.42 GeV] phase shifts and inelasticities with expressions that incorporate analyticity and unitarity.
Peláez Sagredo, José Ramón   +1 more
openaire   +4 more sources

Automating scattering amplitudes with chirality flow

open access: yesEuropean Physical Journal C: Particles and Fields, 2022
Recently we introduced the chirality-flow formalism, a method which builds on the spinor-helicity formalism and is inspired by the color-flow idea in QCD.
Andrew Lifson   +2 more
doaj   +1 more source

Scattering amplitudes in Lifshitz spacetime [PDF]

open access: yesClassical and Quantum Gravity, 2014
We consider the calculation of scattering amplitudes in field theories dual to Lifshitz spacetimes. These amplitudes provide an interesting probe of the IR structure of the field theory; our aim is to use them to explore the observable consequences of the singularity in the spacetime.
Andrade, T., Ross, Simon F., Lei, Y.
openaire   +4 more sources

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